


To break a promise

by heloflor02



Category: Undertale (Video Game)
Genre: Angst, F/M, Goat mom is a mad mom, Lots of Angst, Sans can remember the resets, this is rather dark
Language: English
Status: Completed
Published: 2017-12-08
Updated: 2017-12-08
Packaged: 2019-02-12 07:54:27
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 2,859
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12954729
Author URL: https://archiveofourown.org/users/heloflor02/pseuds/heloflor02
Summary: You sometimes have to realize how much you may lost...





	To break a promise

**Author's Note:**

> This is just a random idea I had some months ago and just re-thought of it and was like “why not ?” so here it is. Hope you'll enjoy and that I'm not out of character !  
> Warning : This is rather dark so I don't think it may be really adapted for people that aren't at least teens.

He was watching.

He was silent, still, barely even breathing; not that he needed to. As the snow was falling, he was there, his back against a tree, looking at the path in front of him. A path leading to a closed place, a path that, for him, went from a warm feeling full of joy to an entrance welcoming a demon.

Rage started to rise in him as he started to remember again on what was happening down there. It was them, this kid, _**this brat**_ , who, for some time now, started to appear down there and decided that mercy was never an option. So they killed; again; and again; everytime; **and always coming back for more.**

His thoughts were interrupted as he suddenly heard a clicking sound, followed by the creaking of a door.  _ The door leading to the Ruins.  _ _**The place where they start it all.** _

It was no long before he could see them, walking in the snow, their shadow casting a dark feeling on the entire forest; and yet, they seemed to have less dust on them. This made him almost chuckle.  _ Heh, as if this  _ _**thing** _ _ would ever think that killing is bad. _ Without another second of thinking, he teleported in front of them, a strong desire of ending this once and for all burning in him.

 

“Heya.”, he said in a normal tone, looking at the child who stepped back in surprise. “Heh, what's wrong buddy ? Ya wasn't expecting me ?”

 

“W-what do you want ?”, they asked once their little fear was passed, a severe look on their face. He closed his eyes, leaving a creepy laugh. Then, he opened them again, eyelights gone.

 

“ **And what do you think I want, huh ? After everything you did, after everything you destroyed to me, to everyone; there's only one thing I wanna do.”**

 

“You don't scare me.”, they responded, still looking severe.

 

“Heh”, he closed his eyes again. “I'm not surprised. Ya never really cared about people's emotions anyways, **did ya ?** But that's not the point anyways.”, he looked back a them with the most serious expression he ever had. “I'm here to do my job, for once. I'm here to kill you, kid; and make sure that you never come back again.”

 

Before they could say anything, bones appeared under them, piercing through them. And as they tried to scream, as they tried to move, as their HP was getting lower and lower; he was watching, feeling some kind of new satisfaction in him, satisfaction to finally see them fall; and hope, hope to fix everything they did.

After one last instant, he stopped his attacked and their body collapsed on the ground. Then, their soul appeared out of their body. Seeing it, he couldn't help smiling. _There you go kid. Looks like you're finally going to do something good down there._

The soul started to look unstable, as if it was about to crack. Without a hesitation, he used his blue magic on it, forcing it to stay still. _Time for you to join some friends. Heh, who am I kidding ? You don't have any friends, especially not friends like these kids who never dared acting like you did._

As he was about to teleport with the soul, he suddenly heard a shocked gasp. Surprised, he looked past the body; only to see a big goat monster at the Ruin's door looking at the corpse in shock. He didn't teleport away, surprised to see a monster alive from where the kid came. After a moment, she turned to face him, looking enraged, fire starting to appear in her hand.

 

“What did you do... **what have you done to them ?!** ”, she shouted.

 

It felt like a stab in the soul. This voice, _her_ voice, he knew it oh to well. It was _her_ , the Lady he met at that door, the one he spent so much time with, the one he grew up to like way more than expected...the one he promised to protect the any human child coming through her door, a child like the one he just killed in cold blood.

 

“...I...”, he started, unsure, before shaking his head, looking more confident. “Look, I know this sounds crazy but I had a good reason to do that. I swear I hated to have to do it but it's the only way !”

 

“You...your voice...”, she looked at him in surprised, her magic looking less powerful. “It's...it's you...”, she started to look even more enraged than before. “I... **I trusted you ! How could you have done this to them ?!** ”, tears started to run down her cheeks as she kept looking at him with the coldest glare he ever saw. His soul hurt again.

 

“I...I did what was best for all of us !”, he shouted, trying to keep his composure. If he wouldn't be able to admit it, he was scared. Scared of what would happen now, scared to have to fight her, scared to know how much she must be hating him right now, after all the time he kept her company, always hoping that they could be more than simple friends. But now...

 

“You killed a child !”, she shouted back at his comment, fire getting bigger and bigger in her hands.

 

“You don't get it ! This kid isn't like all the others ones; they did terrible things to all of us !”

 

“ **Silence !** ”, she finally said before shooting fireballs at him. Though, he expected her to attack and quickly dodged, making sure to keep his blue magic on the soul to avoid having it break. Using his magic, he putted the soul in a pile of snow, where it would not be destroyed if the situation got worse; while still keeping it under his magic.

Looking back to the Lady, he saw her getting past the corpse, looking sadly at it before getting her attention on him again, fire magic ready. She attacked again, aiming at the ground. For a second, he was confused; until fireballs started to appear all around him, coming from the ground and forming a tornado around him. He hesitated for a moment, analyzing the attack, before realizing that the fireballs that got upper started to aim at him. he formed a wall of small bones around him, coming from were the fireballs did and going upper than it into the air.

After this attack, he was able to see her again. She was waiting, fireballs ready again as she was surely preparing for his turn.

 

“Look Lady, can't we just talk about this ?”, he asked, choosing the “mercy option”, feeling unable to hurt her.

 

“There is nothing to talk about.”, she darkly said, attacking again.

 

This time, it was a frontal attack; a bunch of fireballs aiming at him. His first reflex was to throw bones at each one of these to destroy both attacks as a way of defense. However, this created a huge cloud of smoke and, as he tried to see her shadow in it, another row of fireballs appeared and he wasn't quick enough this time, making one of those hurt him in a direct hit and propulsing him a bit in the snow.

As he thought he would die, he saw that his HP were at 0,05/1. He stayed still, looking up as he heard her approach, his bones rattling in a new fear, a fear to die...by the hands of the one he deeply loved.

She looked down to him, tears still rolling down and seeming surprised when she saw how low his HP were. She then looked away with a disgusted expression, dissipating her magic.

 

“You are no worth it.”, she almost murmured. She then turned back to him. “Just give me this soul that your people should never seek...and leave. Leave this place and never come back.”, her voice started to break as more and more tears were falling. Still, she didn't make any sound of crying, neither she was looking less angry. “I do not want to see you there anymore.”, after saying that, she turned away, getting next to the kid's corpse and crouching down next to it, gently closing their eyes.

He still wasn't moving; he didn't want to. The hit he took was still hurting a lot; and it wasn't the only thing killing him. He never felt that much hurt than before seeing her look, seeing how bad she was thinking of him, how much hated she had for him, someone she got to know and started to trust as she was all alone in a quiet place. He knew how much betrayed she must feel, and god this was hurting him like hell ! He wanted all this suffering to end; both him and hers. He wanted to hear her being happy, to hope that she may see him as someone she could trust. He wanted... _fuck_.

He wanted the kid to reset, to fix everything like they did for their actions. And yet, he knew how dangerous they were. _But maybe a good scare and a reminder of how weak they can be next to us may make them regret it and change their acts ? Heh, who am I kidding...but what if it works ?...It_ _ **have**_ _to work..._

He started to try getting up, cursing the pain from his injury. He suddenly heard a quick move and, looking up, he saw that the Lady turned back to him, mistrust in her eyes.

 

“Heh, what's that look for ?”, he asked, a fake smile on as he was feeling another deep pain on his soul. _I'm so sorry I destroyed all your hope like that Lady...I never wished for you to be hurt..._

“It's not like I'm almost dead. There's not much I can do to attack you.”, he continued.

 

She stayed silent, looking at him slowly getting up. She then started to approach him.

 

“Where is the soul ?”, she coldly asked.

 

“Why do ya want it anyways ?”, he said, looking more serious.

 

“I cannot leave Asgore achieve his plan. And...”, she looked over her shoulder to the corpse. “...they may still be hope for them...”, she sadly murmured.

 

“There is...”, he said. “But I need you to trust me on this.”, he quickly added.

 

“Why should I even trust you ?”, she asked, her attention on him again, her hands looking as if she was about to fire again.

 

“Because that's the only thing you can do now to save them.”, he answered, keeping eye-contact with her.

 

She didn't respond, looking even more angry and taking a step towards him. He didn't move, though he felt tense.

 

“Look. Can't we just talk about it like civilized monsters ?”, he asked.

 

“There is nothing to talk about. Just give me this soul and go away.”

 

“Heh.”, he shrugged with a smile, realizing that he won't be able to resolve this by a nice chat. “I'm not going anywhere until I'm sure I won't be followed for the soul.”

 

Fireballs appeared again in her hands.

 

“ **This is my last warning.** I do not care how much injured you are, I will **not** let you go with them !”, despite what she was saying, tears started to form again at the corner of her eyes and her magic wasn't as bright as before.

He stayed put for a second before putting slowly his hands in his hoodie, still smiling at her, as much as it hurt his soul to do so.

 

“You asked for it.”, she said, throwing fireballs.

 

As it was approaching, he started to get ready to dodge. However, they were slower than before and didn't seem to really aim at him. If it was easier to dodge, teleporting to do so took him some energy; and he was already low on HP. _I need to put a stop on all this stupidity._ He thought as he dodged the last ones. Then as the goat monster looked at him for his turn, he made a cage of bones appear around her, surprising her.

 

“What..”, she looked back at him in anger. “Get me out of there !”

 

“Sorry Lady.”, he said, teleporting against a tree, sitting and trying to catch his breath. “The fight's over now. I can't keep fighting like that.” _Especially against someone I don't wanna hurt..._

 

Silence fell for a moment between them.

 

“You are a terrible person.”, the Lady suddenly said, sit in the bone cage and no longer looking enraged. But, with her rage gone, her sadness became more visible and she seemed to be crying more than before. “I should have never trust you.”, her tone was cold.

 

He stared at her for an instant, not knowing what to answer. He then sighed.

 

“You don't understand...”, he murmured almost to himself. “I only did it to protect everyone. This kid is a danger to all of us. They have a power, a power they used way too much. Heh, and here we are now because of them...”

 

“This human is a **child**.”, she started to look mad again.

 

“I...heh. I knew you'd say that. Kids always mattered a lot to you, didn't they ?”, before she could answer, he kept going. “Look, I understand if ya don't wanna trust me; and I'm sorry I brought you so much pain.”, he stopped for a moment, looking at the ground, pensive. _I have to do this._ “I can fix it.”, he was still looking at the ground, almost murmuring. “I can fix all the bad things I did to you. I can...” _I can make you forget all of this, as if it never happened...But I'll never forget how much hurt you were when I betrayed you...I won't do the same mistake twice._

 

He got up, making the soul come in front of him with his blue magic. The soul was still intact with no traces of breaking.

 

“What are you doing ?”, her voice echoed all the tension she had.

 

“Fixing all the bad I did.”, he responded as he stopped his blue magic. At the same time; and because he wasn't in his best state, he left the cage of bones disappear.

The soul fell into his hand. Quickly, he brought him to his chest, leaving it penetrate his body. He heard the footsteps of the Lady who probably wanted to stop him before he suddenly felt an immense pain into his entire being. He fell on his knees, clutching to his chest. Despite the pain, he tried to keep his eyes open, only to see the Lady looking at him in horror.

He started to feel his body change. He felt like his hands got more elongated, claws appearing at the end of it. He also felt himself getting a bit taller; and felt like a tail appearing.

After another minute of deep pain and panic caused by ignoring what would happen to him, he started to feel less hurt and, after a time, he was able to stand. Looking around him, he saw that he badly damaged the tree next to him in his panic. He also saw the Lady, standing there with a shocked expression. After a time, she shook her head, looking at him in disgust.

 

“ **What have you done ?** ”, fireballs appeared in her hands again.

 

“I...” _I need to make this quick before she tries to fight again. If I try to defend myself with an attack, because of the humans soul..._ “I'm doing this for you.”, he said in a serious tone.

 

“Excuse me ?!”, she sounded outraged.

 

Before she could do more, he concentrated on the human soul in him, making a “reset” button appear in front of him.

 

“What...what is that ?”, he couldn't tell if she was scared or mad or chocked or all at the same time. This didn't surprised him. He didn't know what he was feeling anymore either.

 

“The end of everything.”, he responded, looking at the button. “Thanks to this, everything that just happened will be gone and everything will go back to normal.”

 

“Wha-”, before she could finish, he pressed it and everything went white around them. Looking down, he saw that he was himself starting to disappear; and the Lady too. He also started to feel the soul getting out of him, to go back to the body it belongs. He closed his eyes for an instant before turning back to her.

 

“Lady, I'm sorry it had to come to this. I never wished to hurt you that badly; and I won't do the same mistake again...I promise. The same way I promised you something and _will_ keep it; as long as the kid doesn't get completely corrupted by their own LOVE.”, she remained silent, looking both at him and everything around her, in surprise.

Their bodies started to fade more and more; and as their heads were about to be next, he smiled at her, looking deeply in her eyes.

 

“Goodbye Lady. See you on the other side; in a timeline where all this pain and suffering will never exist...I'll make sure of it...

...I love ya.”

 


End file.
